Mice dominate the dungeon

Twitch, a Clash of Clans enthusiast, unexpectedly transmigrates to a perilous dungeon, becoming a lowly rat who can easily crush even goblins. Surrounded by monsters in front and adventurers behind, just when Twitch thinks he won't survive three episodes, he awakens the Clan Lord System. This allows him to obtain elixir and gold by dismantling resources, and to create troops and build his territory. [Mage Rat: Rats wielding various spells cast a terrifying shadow over the battlefield; they will destroy all land and air targets.] [Spring Trap: Once, a cleverly designed spring was placed before me, but I didn't see it, and then, and then, nothing happened.] Following the system's descriptions, Twitch, true to his rat nature, lies low in his territory, building high walls, stockpiling food, and patiently awaiting his claim to kingship! He upgrades his brooder, unlocking rat troops: from basic builder rats to barbarian rats, bomb rat riders, balloon rats, rat witches who summon undead, and even legendary rat heroes emerge, creating an endless rat horde! Upgrade defensive structures and seize control of the ground and sky: Arrow Towers, Cannons, X-Bows, and Inferno Towers rise from the ground, traps abound, walls stretch as far as the eye can see, and the dilapidated rat's nest is gradually transformed into an absolute fortress that even dragons cannot breach! Years later, walls and traps fill the entire dungeon, and the familiar rats, acting on Twitch's will, walk the earth. Twitch sits alone on his throne, softly lamenting, "How did I, a mere rat, become a demon king?" [Mixed Worldview] + [Non-human Protagonist] + [Partial Clash of Clans Settings] + [Infrastructure and Troop Production]